EA006050B1 - Method and device for producing highly condensed polyesters in the solid state - Google Patents

Abstract

The invention relates to a method for producing highly condensed polyesters in the solid phase by means of crystallisation, with or without a subsequent solid-phase polycondensation, for producing bottles, sheets, films and high tenacity commercial fibres.

Description

The present invention relates to a device and a continuous or intermittent method for producing solid phase polycondensed (highly condensed) polyesters using crystallization with or without solid phase polycondensation for making bottles, films and high strength industrial yarns.

Known aromatic polyesters or copolyesters, in particular polyethylene terephthalate and its copolymers with small amounts, for example, isophthalic acid, or cyclohexanedimethanol, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene terephthalate and its polyol terephthalate, which serve as a raw material for the polytrimethylene terephthalate, polyethylene terephthalate and polyol terephthalate, which serve as a raw material for the production of polytrimethylene terephthalate, polyethylene terephthalate and polyol terephthalate, which serve as a raw material for poly (trimethylene terephthalate) complex polyester melted at the stage of melt polycondensation, lead to the state of the average final viscosity. The average degree of polycondensation, expressed in intrinsic viscosity (X.V.), extends in the range from 0.30 to 0.90 dl / g in polyethylene terephthalate and its correspondingly low-modified complex copolyesters after melt polycondensation.

Since the manufacture of granules with Kh.V. higher than 0.65 dl / g is hardly possible, in particular, in conventional autoclaves, and high viscosities> 0.80 dl / g lead to a significant decrease in melt polycondensation productivity, and since, moreover, polyesters used for food packaging , require a very low content of acetic aldehyde, polycondensation of the melt of the prior art was followed by solid phase polycondensation (DFT), which led to an increase in H.V., in general, by 0.05-0.4 dl / g and to a decrease in the content of acetaldehyde from about 25100 ppm. mil to values <1 part for mil in polyethylene terephthalate (PET).

With this solid phase polycondensation, following the melt polycondensation stage, the average viscosity increased in such a way that the strength required for the respective application area was reached, the content of acetaldehyde in the case of food packaging decreased in accordance with the requirements, and the content of the living oligomer was reduced to the minimum value. Therefore, it is important here that acetaldehyde, which has a vinyl ester bond, also referred to as precipitated acetaldehyde, is decomposed to such an extent that during processing of polyester granules into packaging, in particular polyester bottles, according to the blowout and injection method blowing out only a minimum amount of acetaldehyde was re-separated (re-formed) in the polyester. In particular, when mineral water is poured into polyester bottles, less than 2 parts. On mil acetaldehyde should be contained in the walls of the bottle, consisting of polyethylene terephthalate.

In addition to DFT, methods are known for the dealdegization of polyethylene terephthalate by treatment with nitrogen or dry air, as described in US Pat. No. 4,230,819. To obtain the required low content of acetaldehyde in the material, temperatures up to 230 ° C were used. When air is used, strong decomposition due to thermal oxidation of the polyester at such elevated temperatures should be expected. When using nitrogen increases the cost of gas and complex cleaning.

US patent 4,223,128 excludes temperatures greater than 220 ° C when air is used as the carrier gas. This patent describes the required increase in x.v. with the help of large quantities of dry air at a dew point of -40 to -80 ° C and at a processing temperature of 200 ° C, as shown in the examples of this patent, oxidative destruction of individual granules of the granulate can be excluded in continuous ways that have a more or less wide range of the residence time of the material during processing.

DFT achieves elongation of polyester chains in the solid phase to keep side reactions as low as possible, which are manifested to a greater extent in the melt, as well as removal of harmful by-products. With such lengthening of chains, which is expressed by an increase in H.V., it is possible to manufacture products such as bottles or tire cord that require increased strength.

However, since polyesters are partially crystalline thermoplastic materials, they contain a more or less amorphous phase, depending on their type. When DFT is performed, this fact causes problems due to the amounts of the amorphous phase at the temperatures required for DFT, which lead to sticking, which in turn can even lead to the shutdown of the production plant.

Therefore, it is also known that as a preceding operation, crystallization of partially crystalline crumbs from melt polycondensation is carried out before DFT to prevent any tendency to stick together under conditions of nitrogen or air at temperatures in the range 160210 ° C, as described in US patents 4.064.112, 4.161. 578 and 4.370.302.

International application AO 94/17122 discloses 2-stage crystallization with preheating and intermediate cooling before DFT to prevent sticking. The temperature range of the described DFT extends from 205 to 230 ° C.

To improve the quality of the crumbs, it is possible to use, as described in Japanese patent 09249744 or US patent 5.663.290, wet inert gas before or during the DFT, or, as disclosed in US patent 5.573.820, the crumbs can be pre-treated intensively with hot water or directly with water vapor at temperatures up to 200 ° C before crystallization. However, in this case

- 1 006050 Tea should expect a strong undesirable drop in the H.V. as a result of hydrolysis in PET at standard temperatures> 190 ° C.

Another way is to treat the crumb undergoing crystallization with purified non-dry nitrogen from DFT in countercurrent in the second crystallization stage, as shown in European patent EP 222714. The effect of reducing the content of acetaldehyde described here can hardly be considered significant.

These crystallization steps are intended to reduce the amount of the amorphous polyester phase to such an extent that DFT can be performed without any sticking.

The main differences between the characteristics of DFT and crystallization are the following.

1. The residence time of the material during processing in the case of crystallization is significantly shorter than in DFT, and averages 3 hours compared with 5-40 hours in DFT, and

2. in the case of crystallization, physical processes predominate, as it becomes, for example, evident from the usually very insignificant growth in X.V. from 0.01 to 0.02 dl / g, whereas chemical reactions take place in the case of DFT, as can be seen from the growth in X.V., which is usually from 0.2 to 0.3 dl / g.

Therefore, the aim of the present invention is to develop a method for producing solid phase polyesters that can be carried out easily and which at the same time helps to maintain or improve, in particular, the high quality standards required from polyesters for packaging in terms of color, molecular weight distribution, content of acetaldehyde, re-allocation of acetaldehyde, the amount of oligomers and the tendency to stick together, and also significantly reduces the formation of waste and dust.

According to the invention, this goal is achieved by a method for producing polyesters, including crystallization of a polyester material, characterized in that crystallization is carried out in two stages, in which a partially crystalline polyester material is obtained in the first stage, and a partially crystalline polyester material in the second stage, suitable for crystallization (ί) with mechanical perturbation and gas in countercurrent, () with mechanical perturbation and gas in parallel flow and () es mechanical disturbance and gas in parallel flow.

This method is suitable for the production of granules of partially crystalline aromatic polyesters or copolyesters obtained from one or more dicarboxylic acids or its methyl esters, such as terephthalic acid, isophthalic acid and / or 4,4-bisphenyldicarboxylic acid, and one or more diols, such like ethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol and / or diethylene glycol.

These starting compounds can be treated in a known manner, according to the continuous or batch method of esterification or transesterification, using known catalysts, followed by melt polycondensation in vacuum to obtain a polyester material, preferably in the form of granules.

Polyethylene terephthalate homopolymers and copolymers are preferably used with comonomer content of less than 10% by weight.

In the first stage of the process according to the invention, a partially crystalline polyester material is obtained. The partially crystalline polyester material has a degree of crystallization of approximately 40-48%.

In order to obtain a polyester material in the first stage of the process according to the invention, any suitable and partially crystalline polyester material can be used. A partially crystalline polyester material can be obtained by crystallizing a polyester material obtained from melt polycondensation. Preferably, to obtain a polyester material in the first stage of the process according to the invention, the amorphous polyester material obtained after melt polycondensation, preferably granulate, is treated in the first stage to increase the degree of crystallization from about 40 to about 48% by swirling through a gas stream at appropriate temperatures and times material stays during processing. The preferred temperature range will be from about 170 to about 210 ° C and the preferred values of the residence time of the material during processing will be up to about 30 minutes, preferably from about 10 to about 30 minutes.

The preferred gas used for turbulence will be air and / or nitrogen.

The partially crystalline polyester material is preferably prepared by means of a fluidized bed reactor. In particular, the first crystallization stage is carried out in two zones, the crystallization in the first zone 1 is performed in a fluidized bed with mixing characteristics and the crystallization in the second zone 2 is performed in a fluidized bed with a controlled flow of granulate.

FIG. 1 shows a preferred embodiment of a fluidized bed reactor 20, through which the crystallinity of the polyester granulate is raised to the desired degree, in particular to 40-48%. The granulate is fed here via a conveyor device 10 to a fluidized bed mold 20, which is provided with rectangular surfaces that create

- 2 006050 fluidized bed, and which has two zones 30, 50, where the granulate crystallizes at elevated temperatures of 170-210 ° C, and as an embodiment, with dry gas and a dew point from 20 to -50 ° C.

The gas / crumb ratio may be 3-4 in the first zone and 2-3 in the second zone with the residence time of the material during processing 10-30 minutes.

As shown in FIG. 1, the gas can be directed in such a way that it will be distributed over the perforated sheet and pass into the first zone 30 through the gas inlet 40 with a gas velocity of 3.2-4 m / s, and also enter the second zone 50 through the window 40 ' gas inlet with a gas velocity of 2.1-2.7 m / s (speed in vacuum) and leave the mold again through the connected gas outlet 60 in the upper region. This method of directing gas leads to the formation of a fluidized bed with mixing characteristics in the first zone 30 and to a vortex controlled flow of granulate in the second zone 50. The amount of dust at the outlet of the mold is <10 ppm. on mil

The granulate obtained after the first crystallization stage has a preferred degree of crystallization in the crumb, amounting to approximately 40-48%.

The partially crystalline polyester material that can be used according to the invention, preferably granulate, flows in a second stage at temperatures suitable for crystallization (ί) under mechanical disturbance and gas in countercurrent, () under mechanical disturbance and gas in a parallel flow and ( ίίί) without mechanical disturbances and gas in a parallel flow.

The flow of a polyester material in the context of the description of the present invention means the movement of the polyester material in one direction, for example a movement caused by gravity and / or mechanical transport.

Steps (ί) - (ίίί) of the second stage of the method according to the invention are carried out, in particular, preferably in a continuous manner, that is, the material of the polyester passes through the steps () - (ίίί) in a continuous stream. The polyester material, however, can be treated in portions in steps (ί) - (ίίί). Steps (ί) - (ίίί) are preferably carried out in the sequence indicated. However, it is also possible to stage () - (ίίί) in any other sequence.

In steps (ί) - (ίίί) of the second stage, gas is used, preferably air or nitrogen, in particular, nitrogen is used.

The temperature used for crystallization in steps (ί) - (ίίί) of the second stage is from about 190 to about 220 ° C, more preferably from about 190 to 215 ° C, and particularly preferably from 200 to 210 ° C.

The residence time of the polyester material during processing at the stage (ί) of the second stage is from about 30 to about 60 minutes, at the stage (ίί) of the second stage from about 30 to about 60 minutes, and at the stage () of the second stage from about 60 to about 180 min.

The second stage of crystallization is particularly preferably carried out in three zones of a shaft-type mold with blades, namely in zones 3, 4 and 5, in which steps (ί) - (ίίί) of the second stage are carried out, while in zone 3 the granules are subjected to periodic increasing mechanical perturbations with gas in counterflow, in zone 4 - to a periodic increasing mechanical disturbance with gas in a parallel flow, and in zone 5 - without mechanical disturbance and with gas in a parallel flow.

The second stage of crystallization is preferably carried out in the device according to the invention for the preparation of polyesters. A device (70) according to the invention for crystallizing a polyester material in the form of granules, for example a shaft-type mold with blades, contains three consecutive sections (80, 90, 100), at least one inlet window (110) formed in the first section (80), at least one window (12) for release, formed in the third section (100), means (130), leading to the formation of a mechanical perturbation of the polyester material, which is installed in the first and second sections (80, 90) at least one gas inlet window (140), forming Noe in the transition region between the first and second sections, and at least one window (150, 160) for discharging gas is formed in the first and third sections.

In a preferred embodiment, the device according to the invention includes means (130) for forming a periodic mechanical perturbation with a shaft (170) on which at least one lever is mounted, and preferably six or more levers (180, 180 '), which cause a mechanical disturbance of the current polyester material when the shaft (170) rotates. This means may also include a first shaft and a second shaft, with at least one lever mounted on each shaft.

FIG. 2 shows a preferred embodiment for a device according to the invention, namely a mold (70) of a shaft type with blades, in which the second stage of the method according to the invention can be carried out. The granulate is introduced in a second stage, as shown in FIG. 2, into a continuously operating vertically mounted three-section mold (70) of a shaft type with blades, having a rotating shaft mounted centrally along the longitudinal axis. In the first and second sections (80, 90) of a shaft-type mold with blades in zones 3 and 4 on the shaft, the arms (180, 180 ') are installed at certain intervals and create low resistance to flow;

- 3 006050 Periodic mechanical perturbation of the bulk material. Due to the movement of the granules prevent the formation of agglomerates (adhesion) of the material. In the third section (100) of a shaft-type mold with blades, the granules are treated in zone 5 without any disturbance.

In the third and fifth zones, the granules are periodically subjected to mechanical perturbation, whereas in the fifth undisturbed zone, the residence time of the material during processing is kept uniform at the beginning of post-polycondensation.

The gas is directed so that it is fed between the third and fourth zones (the first and second sections of the mold of the shaft type with blades) through the window (140) for gas inlet, and the gas leaves the mold again in the upper or first section (80) through the window (150) for the release of gases and in proportion to the amount also leaves the mold in the lower or third section (100) through the window (160) for the release of gas. Here, the gas is directed to the third zone (the first section of the mold of the shaft type with blades) in countercurrent with respect to the granules and to the fourth and fifth zones in a parallel flow (the second and third section of the shaft-type crystallizer with blades).

The gas outlets (150, 160) are preferably formed so that the gas introduced through the gas inlet window (140) is directed with the pellets in countercurrent or parallel flow for as long as possible, i.e. at the beginning of the first section (180) and at the end of the third section (100) of the mold (70) of the shaft type with blades.

In the third zone (the first section (80) of the mold (70) of the shaft type with blades), PET granules are heated when exposed to a periodic mechanical disturbance, preferably with hot gas, in particular nitrogen, in countercurrent with respect to the granules with a gas / crumb ratio of 1-3 , and with the residence time of the material during processing for at least 30-60 minutes to a temperature of 190-220 ° C.

In the fourth zone (the second section (90) of the mold (70) of the shaft type with blades) PET granules undergo further crystallization and turn into a homogeneous material with periodic mechanical disturbance, preferably at a temperature of 190-220 ° C with gas, in particular nitrogen, in parallel flow and gas / crust ratio of 0.5-1. The residence time of the material during processing is at least 30-60 minutes.

PET granules thus treated in the third and fourth zones are treated in the unperturbed fifth zone (section (100) of the mold (70) of the shaft type with blades) at a temperature of 190215 ° C in a parallel flow with a gas / crush ratio of 0.1- 1, and in such a way that with an average residence time of 60-180 minutes, a slight postpolycondensation already occurs in this zone, in addition to reducing the amount of aldehyde and crystallization. According to the method of the present invention, the tendency to sticking of the granules is thereby significantly reduced.

The total residence time of the polyester material in the first and second crystallization stages, provided that it includes staying in the above zones 1-5, will preferably be 100-350 minutes, in particular 130-330 minutes, while the ratio of the residence time of the material on the first stage to the residence time of the material in the second stage will be from 1: 4 to 1:32. In this case, a particularly preferred ratio of the residence time in the first and second crystallization stages, provided that the said stages include zones 1-5, is such that the residence time in zones 3 and 4 is 4-6 times longer than the residence time in zones 1 and 2, and the time spent in zone 5 was 2-3 times longer than the time spent in zones 3 and 4.

The polyester material used in the process of the present invention preferably has an X.V. equal to at least about 0.3 dl / g, and more preferably from about 0.3 to about 0.9 dl / g, and especially preferably from about 0.3 to 0.8 dl / g, and preferably from about 0.66 to 0.9 dl / g, and particularly preferably from about 0.72 to 0.8 dl / g. It is particularly preferred that a polyester material is used which has an X.V. at least equal to about 0.66 dl / g, more preferably from about 0.66 to 0.8 dl / g, and particularly preferably from about 0.72 to 0.8 DL / g, since the material thus obtained has the required low content of acetaldehyde, namely <10 ppm. On mil, in particular <1 part. It is fine and therefore suitable for further processing without subsequent DFT into molded polyester products, for example bottles that require a low content of acetaldehyde. Surprisingly enough, it has now been discovered that a polyester material such as a granulate can be used with a high X.V., when the method according to the present invention is carried out.

When using a polyester material with an X.V. of at least about 0.3 to about 0.72 dl / g, TFT is preferably performed subsequently.

Since the partially crystalline polyester complex during crystallization in the crystallizer and in the reactor of subsequent solid phase polycondensation can lead to the formation of agglomerates to an increased degree due to the formation of a large amount of exothermic heat and since such sticking can be quite strong and such that they are no longer separated from each other. when using standard crystallization and solid phase polycondensation methods, the use of spherical polyester material will preferably be itelnym in the process according infusion

- 00 005050 to the invention. However, it is also possible to use other forms of granulate, for example a cylindrical or scaly form.

Cylindrical granules are not preferred, however, since they easily stick together due to their surfaces and edges, they also show increased wear. Due to the asymmetry of cylindrical chips, it is difficult to obtain a uniform crystallization from the outer surface to the core of the crumb. Compared to balanced cylindrical chips, the use of approximately spherical chips provides the advantage of a more uniform crystallization, an improved molecular weight distribution in the crumb, as well as an improved mass per unit volume of bulk material, which is 5-10% higher. The amount of dust that is lower when using spherical chips is also an additional significant advantage.

Especially preferred is the situation when the granules used have a specific surface in the range of 1.45-2.0 m ² / kg, and more preferably a specific surface in the range of 1.50-1.85 m ² / kg.

The granules obtained according to the method of the present invention preferably have a uniform degree of crystallization of about 49-53%, in particular about 52%, and these granules are pretreated in these crystallization techniques in such a way that the sticking of PET granules due to exothermic reactions in possibly subsequent solid phase postcondensation can be avoided.

The granules obtained according to the invention have an acetaldehyde content of <10 ppm. On mil, preferably 0.5-5 part. On mil and especially preferably <1 part. on mil

According to the invention, the amount of dust from the granules is preferably <10 ppm. on mil after crystallization.

It was surprising to find out that when using the method of the invention with 2-stage crystallization, in particular when using fluidized bed crystallization and a shaft-type crystallizer with blades, polyester granulate can be obtained with low content of acetaldehyde, slight re-formation of acetaldehyde, with high brightness of coloring, very low values of dust, without sticking, and when using crumbs from high X.V. in the range of 0.66-0.90 dl / g from the melt polycondensation, subsequent solid state polycondensation can be avoided.

The granules obtained according to the invention preferably have variations in X.V. less than 1.5%.

The present invention also relates to a method for producing molded products from polyesters, a material from polyesters, in particular granules, which can be obtained according to the method of the invention without any solid polycondensation.

In particular, the material of polyesters, preferably in the form of granules or crumbs, which were obtained according to the method of the present invention, and with a value of X.V. from melt polycondensation> 0.66 dl / g, can be easily supplied without any further condensation to the solid-state polycondensation reactor for processing according to the blow-out method or the blow-out injection method to obtain polyester molded products. On the other hand, the polyester material with a lower X. V. can be subjected, after polycondensation of the melt and carrying out the crystallization method according to the invention, at a subsequent stage of standard solid-phase polycondensation, which is carried out continuously or periodically, and this material can then be used to obtain molded products from polyesters.

Polyester moldings are preferably selected from the group consisting of bottles, sheets, films, and high-strength industrial yarns.

The invention will now be described in more detail with reference to several embodiments that in no way limit the scope of the invention. The characteristic values, as shown here, were defined as follows.

Characteristic viscosity (X.V.) was measured at 25 ° C in a solution of 500 mg of polyester in 100 ml of a mixture consisting of phenol and 1,2-dichlorobenzene (3: 2 weight ratio).

The concentration of the COOH end group was determined by photometric titration with a 0.05 ethanol solution of potash liquor relative to a blue bromotinol solution of a polyester in a mixture of o-cresol and chloroform (weight ratio 70:30).

Diethylene glycol (DEG), isophthalic acid (IFC) and 1,4-cyclohexanedimethanol (CHDM) were determined in a polyester by gas chromatography after previous methanolysis 1 g of polyester in 30 ml of methanol with 50 mg / l of zinc acetate in a sealed tube at 200 ° s

Turbidity values in nephelometric cloud units (NEP) were measured in a 10 wt.% Solution of polyester in phenol / dichlorobenzene (3: 2 weight ratio) using a Khach (Nasi) nephelometer (type HK, according to US Pat. No. 4,198,161) in a cuvette. having a diameter of 22.2 mm, by analogy with the standard ΌΙΝ 38404, part 2, which is usual for water. The intensity of the scattered light was measured in comparison with a standard formalin solution minus the solvent (about 0.3 NEP).

The color intensity values b and b were measured according to Hunter (ΗυΝΤΕΚ). Polyester crumbs were first crystallized in a drying oven at a temperature of 135 ± 5 ° C for 1 h.

The intensity of the color was then determined by measuring the color of the sample of the polyester sample in a three-band colorimeter with three photocells, each of which was installed upstream of the red, green, and blue filters (X,, and Ζ values). Evaluation was performed according to the formula of Hunter, in which

LMO / YI = th __________ λ / Υ (Υ-0.8467)

Acetic aldehyde was displaced by heating in a closed polyester vessel, and acetic aldehyde was detected in the gas chamber of the vessel by gas chromatography with an injection system into the free space H540, developed by Perkin Elmer (Regksh E1teg), the carrier gas was nitrogen, column - 1 , 5 m from special steel, filling packing - Poropak (Rogorask) p, sieve mesh - 80-100 mesh, sample amount - 2 g, heating temperature - 150 ° C, heating time - 90 minutes.

To detect the re-release rate of acetaldehyde, PET crumbs were crushed and the crushed material was melted in a thermodesorber under certain conditions (300 ° C and three temporary periods of material retention: 12-25 min). The content of the resulting acetaldehyde adsorbed on Tenax (Tepach) was then detected by gas chromatography.

Dust analysis was performed using gravimetry. To this end, 1 kg of crumbs were washed with methanol, the washing agent was filtered through a filter, and the residue was dried and weighed.

Example 1 (comparative).

In example 1, almost amorphous cylindrical crumbs weighing 15.5 mg / crumb, with a specific surface area of 1.85 m ² / kg, a mass of a unit volume of bulk material of 790 kg / m ^3, and an X.V. equal to 0.612 dl / g were crystallized according to melt polycondensation method to obtain slightly modified PET for bottles filled with carbonated non-alcoholic beverages (HDN), water or other filled medium, and subjected to solid-phase polycondensation.

Example 2

In example 2, almost round crumbs weighing 15.5 mg / crumb and a specific surface area of 1.55 m ² / kg, and a mass of a unit volume of bulk material of 840 kg / m ^{3 were used} , and they were subjected to crystallization and then solid-phase polycondensation according to standard methods according to with the method of the present invention.

The material used in examples 1 and 2.

The contents of the catalyst 8 b: 200 frequent. On mil, the phosphorus content: 17 part. On mil, cobalt: 15 chast. On mil, blue dye: 0.5 part. on mil, isophthalic acid: 2 wt.%, diethylene glycol: 1.3 wt.%.

The results of example 1 are given in table. 1.1, and the results of example 2 - in the table. 1.2.

Table 1.1

Example 1 (standard crystallization followed by DFT)

Analyzes Material used: cylindrical crumb shape 1. Fluid bed crystallizer Y \ Y2: 60 min. T: 200 ° C 2. Shaft type crystallizer with ν \ νΖ blades: 75 min. T: 219 ° C DFT ν \ νΖ: 12 h. T: 208.5 ° C Δ X.V. = 0,200 (dl / g.) H.V. (dl / g.) 0.612 0.617 0.621 0.812 COOH (mmol / kg) 27 28 26 28 Differential Scanning Colorimetry (DSC) Tt / Tk / Td (° C) 250/143/78 250.5 / 145 / 79.7 Color b 82.7 84.9 87.7 89 Colors -1,6 -1,4 -1,4 -1,4 Color b -3.6 -0,8 -0.7 -0.5 Acetic aldehyde (often, mil.) 45 9.1 3.5 0.5 CTO (° С) - 48.5 51 55,6 Re-formation of acetaldehyde (often, mil.) Dust (often, on mil.) - <10 > 500 > 500

ΥΑΖ material dwell time, T = temperature, CTO — Kuster thermometer (KI)

- 6 006050

Table 1.2

Example 2

Analyzes Material used: spherical crumb shape 1. Crystallization (zone 1 and 2) Fluidized bed crystallizer ν \ ΥΖ: 60 min. T: 200 ° C 2. Crystallization Shaft type crystallizer with blades (zones 3-5) UU / Ζ: 180 min. T: 215 ° C DFT νΨΖ: 12 hours. T: 207.5 ° C Δ X.V. = 0.240 (dl / g.) H.V. (dl / g.) 0.602 0.616 0.636 0.842 COOH (mmol / kg) thirty 27 26 26 Differential Scanning Colorimetry (DSC) TT / Tc / Td (° C) 250/143 / 78.4 - - 251/145 / 80,1 Color b 83 85.1 88.1 89.4 Colors -1,7 -1,4 -1.3 -1.3 Color b -3,3 -1.0 -0,6 -0,6 Acetic aldehyde (often, mil.) 55 8,8 one 0.2 CTO (° С) - 46.1 53.1 55.2 Re-formation of acetaldehyde (often, mil.) - - - 9.3 Dust (often, on mil.) <10 <10 <10 <10

Examples 3 and 4.

In the next test, almost round crumbs weighing 15.5 mg / crumb, with a specific surface area of 1.55 m ² / kg, a mass of a unit volume of bulk material are 840 kg / m ^3, and with a high X.V. about 0.79-0.80 dl / g, obtained according to the melt polycondensation method, were treated with two different catalyst systems according to the crystallization method of the present invention to obtain ready-made bottle granules, so that further processing of slightly modified PET crumbs was easily achieved filled with non-alcoholic beverages, water or other medium to be filled. The results are shown in Table. 2.1 and 2.2.

The material used in example 3 is shown in table. 2.1. Catalyst 8b contents: 250 ppm. On mil, the phosphorus content: 50 part. On mil, cobalt: 25 chast. On mil, blue dye: 1.0 part. on mil, isophthalic acid: 2 wt.%, diethylene glycol: 13 wt.%.

Table 2.1

Example 3

Analyzes Material used: spherical crumb shape Catalyst: 850 part of 250, for mil. 1. Crystallization (zone 1 and 2) Fluidized bed crystallizer νΨΖ: 60 min. T: 200 ° C 2. Crystallization (zones 3-5) Shaft type crystallizer with νΨΖ blades: 180 min. T: 215 ° C Δ Х.В. = 0,017 (dl / g.) H.V. (dl / g.) 0,804 0.799 0.812 COOH (mmol / kg) 22 20 18 Differential Scanning Colorimetry (DSC) TT / Tk / Ty (° C) 248/152/79 - - Color b 76 85 86.5 Colors -2 -1,7 -1.5 Color b -5,5 -3,3 -2 Acetic aldehyde (often, mil.) 80 15 3.2 CTO (° С) - 47.1 52.6 Re-formation of acetaldehyde (often, mil.) - - 9.5 Dust (often, on mil.) <10 <10 <10

- 7 006050

The material used in example 4 is shown in table. 2.2.

The contents of the catalyst ECOSAT В®: metal: 5 part. On mil, phosphorus: 10 chast. On mil, blue / red dye: 1.5 / 1.25 part. on mil, isophthalic acid: 2.0 wt.%, diethylene glycol: 1.3 wt.%.

Table 2.2

Example 4

Analyzes Material used: spherical crumb form Catalyst: ESOCAT B®: metal: 5 parts per mil. 1. Crystallization (zone 1 and 2) Fluidized bed crystallizer νψΖ: 60 min. T: 200 ° C 2. Crystallization (zones 3-5) Shaft type crystallizer with νψΖ blades: 180 min. T: 215 ° C Δ X.V. = 0.032 (dl / g.) H.V. (dl / g.) 0.795 0.797 0.827 COOH (mmol / kg) 15 14 13 Differential Scanning Colorimetry (DSC) Tt / Tk / Tg (° C) 248/152 / 79,5 - - Color I. 72 81 84 Colors -3,5 -2,2 -2 Color b 1.4 1.7 1.9 Acetic aldehyde (often, mil.) 40 7.9 0.8 CTO (° С) - 47.8 52.7 Re-formation of acetaldehyde (often, mil.) - - 8.9 Dust (often, on mil.) <10 <10 <10

Before pressing into preformed blanks and bottles on a single-stage A8B machine (on an injection stretch blow molding machine) of the type 250 EX NAT, with a 6-cavity tool and a capacity of 800-1000 bottles / h, the material was dried in a Challenger dryer (Syayepdeg) at a temperature of 170 ° C for 4 hours

Preformed blanks and bottles were made without any problems. The transparency of the bottles was good, the color neutral. The content of acetaldehyde according to the standard free-space injection method was 1.6-1.9 jg / l in bottles according to the method of the present invention, while its contents in bottles manufactured according to conventional solid phase polycondensation with cylindrical chips are 2.2-2. , 6 cg / l. The mechanical properties of the bottles did not differ from each other.

Claims (18)

CLAIM 1. A method for producing polyesters, including crystallization of the material of the polyester, characterized in that the crystallization is carried out in two stages, in which the first stage produces a partially crystalline material of the complex polyester, in the second stage, the flow of the partially crystalline material of the polyester at temperatures suitable for crystallization (1) with mechanical perturbation and gas in countercurrent, (and) with mechanical perturbation and gas in parallel flow and (возм) without mechanical perturbation and gas in parallel flow. 2. The method according to claim 1, in which the partially crystalline polyester material obtained in the first stage has a crystallization degree of from about 40 to 48%. 3. The method according to any one of the preceding paragraphs, in which the partially crystalline polyester material is obtained in the first stage by treating the polyester by swirling in a gas stream and at elevated temperatures from about 170 to about 210 ° C and a residence time of the material up to about 30 minutes 4. The method according to claim 3, wherein the swirling of the polyester material is performed in a fluidized bed crystallizer. 5. The method according to claim 4, in which at the first stage the swirl is performed in the first zone in a fluidized bed having mixing characteristics, and in the second zone in a fluidized bed with a controlled flow of granulate. 6. The method according to claim 5, in which the gas turbulence is carried out at a gas flow rate of from about 3.2 to 4 m / s in the first zone and a gas flow rate of from about 2.1 to 2.7 m / s in the second zone. 7. The method according to any one of the preceding paragraphs, which use the temperature in the second stage from about 190 to about 220 ° C. - 8 006050 8. The method according to any one of the preceding paragraphs, in which the residence time on the step (ί) of the second stage is from about 30 to about 60 minutes, on the step (ίί) of the second stage, the residence time is from about 30 to about 60 minutes, and on the step (ίίί) of the second stage, it is from about 60 to about 180 minutes. 9. The method according to any one of the preceding paragraphs, in which the second stage is carried out in a mold-type shaft with blades. 10. The method according to any one of the preceding paragraphs, in which the polyester material used is a granulate, preferably a spherical granulate. 11. The method according to any one of claims 2-10, wherein the total residence time of the polyester material in the first and second stages is from about 100 to 350 minutes. 12. The method according to any one of claims 2-11, wherein the ratio of the residence time of the polyester material in the first stage to the residence time in the second stage is from about 1: 4 to 1:32. 13. The method according to any one of the preceding paragraphs, in which the polyester material used during crystallization has an intrinsic viscosity (X.V.) of at least 0.3 dl / g. 14. A method of producing molded products from polyesters, characterized in that they use a material of polyesters, which can be obtained according to any one of the preceding paragraphs without solid-state polycondensation. 15. The method according to 14, in which the molded products of polyesters selected from the group consisting of bottles, sheets, films and high-strength technical threads. 16. Device (70) for crystallization of polyester materials in the form of granules, comprising three successive sections (80, 90, 100), at least one inlet window (110) formed in the first section (80) of at least , one outlet window (120) formed in the third section (100), means (130) leading to the formation of a mechanical perturbation of the polyester material, installed in the first and second sections (80, 90), at least one window ( 140) for the gas inlet formed in the transition region between the first and second sections (80, 90), and, p at least one window (150, 160) for discharging gas formed by both the first (80) section and the third (100) section. 17. The device according to clause 16, in which the means (130) includes a shaft (170) on which at least one lever (180) is mounted. 18. The device according to clause 16, in which the tool, leading to the formation of a mechanical disturbance of the material of the polyesters, contains a first shaft and a second shaft, with at least one lever mounted on each shaft.